Arrangement in an air bearing

Abstract

An air bearing of the type having a first component with a first surface and a second component with a first surface, wherein the surfaces are movable relative to each other with a small space provided between the first surfaces. At least one of the surfaces facing each other being provided with a groove pattern producing during mutual movement of the components a pumping effect in a gas medium provided between the groove provided surface of the one component and the counter-surface of the other component for creating a thin medium film preventing physical contact of the surfaces during mutual motion. The counter-surface is provided with a thin coating for preventing wear at contact between the surfaces.

What is claimed is:  
     
         1 . An air bearing comprising a lower bearing washer having a grooved surface facing a counter-surface of an upper bearing washer, the grooved surface being formed by a plurality of grooves, at least one of the lower and upper bearing washers being rotatable relative to the other bearing washer with a space provided between the grooved surface and the counter-surface to produce during rotation a pumping effect in a gas medium provided between the grooved surface and the counter-surface to create a medium film inhibiting physical contact between the grooved surface and the counter-surface, the counter-surface being provided with a coating having a Vickers hardness above 1000 HV and a coefficient of friction less than about 0.2μ for inhibiting wear at contact between the counter-surface and the grooved surface.  
     
     
         2 . The air bearing according to    claim 1   , wherein the coating is a material having a lower coefficient of friction, and a higher hardness than the material forming the upper bearing washer.  
     
     
         3 . The air bearing according to    claim 2   , wherein the coating is metal mixed diamond like carbon (Me-DLC).  
     
     
         4 . The air bearing according to    claim 1   , wherein the coating is metal mixed diamond like carbon (Me-DLC).  
     
     
         5 . The air bearing according to    claim 1   , wherein the plurality of grooves are helically arranged grooves having an increasing width.  
     
     
         6 . An air bearing comprising a first bearing washer having a grooved surface facing a counter-surface of a second bearing washer, at least one of the first and second bearing washers being rotatable relative to the other bearing washer with a space provided between the grooved surface and the counter-surface to produce during rotation a pumping effect in a gas medium provided between the grooved surface and the counter-surface to create a medium film inhibiting the grooved surface and the counter-surface from physical contact, the counter-surface being provided with a coating having a coefficient of friction between about 0.1μ and about 0.2μ for inhibiting wear at contact between the counter-surface and the grooved surface.  
     
     
         7 . The air bearing according to    claim 6   , wherein the coating is a material having a lower coefficient of friction, and a higher hardness and/or resistance to wear than the material forming the second bearing washer.  
     
     
         8 . The air bearing according to    claim 7   , wherein the coating is metal mixed diamond like carbon (Me-DLC).  
     
     
         9 . The air bearing according to    claim 6   , wherein the coating is metal mixed diamond like carbon (Me-DLC).  
     
     
         10 . The air bearing according to    claim 6   , wherein the grooved surface of the first bearing washer includes helically arranged grooves.  
     
     
         11 . The air bearing according to    claim 10   , wherein the helically arranged grooves possess a width that increases in a radially outward direction of the first bearing washer.  
     
     
         12 . An air bearing comprising a first component with a first surface and a second component with a first surface, the first surfaces of the first and second components facing one another and being relatively movable with respect to one another with a space provided between the first surfaces of the first and second components, the first surface of at least one of the components forming a counter-surface and the first surface of the other component having a groove pattern which produces during mutual movement of the components a pumping effect in a gas medium provided between the surface having the groove pattern and the counter-surface for creating a thin medium film preventing the first surfaces from physical contact during mutual motion, the counter-surface being provided with a coating for preventing wear at contact between the first surfaces.  
     
     
         13 . The air bearing according to    claim 12   , wherein the coating is applied on the surface by a depositing method.  
     
     
         14 . The air bearing according to    claim 13   , wherein the coating is a material having at least one of a lower coefficient of friction, a higher hardness and a higher resistance to wear than the material forming the component.  
     
     
         15 . The air bearing according to    claim 14   , wherein the coating is metal mixed diamond like carbon (Me-DLC).  
     
     
         16 . The air bearing according to    claim 12   , wherein the coating is a material having at least one of a lower coefficient of friction, a higher hardness and a higher resistance to wear than the material forming the component.  
     
     
         17 . The air bearing according to    claim 12   , wherein the coating is metal mixed diamond like carbon (Me-DLC).  
     
     
         18 . The air bearing according to    claim 12   , wherein the groove pattern includes helically arranged grooves.